The dress -- which Cotter knows very little about other than he thinks it's probably silk -- "looks pretty good, surprisingly. I mean it's dirty."
He has photographed about 40 uses so far, though only about two dozen have popped up on the blog. Most were shot during the fall.
And there have been some casualties -- Cotter is trying to keep the dress intact through the end of the project, but in the fall, the bow fell off while he was jump-roping.
With the blog picking up steam among friends and random Internet readers alike, Cotter finally broke down last week and told his ex what he'd been up to.
"It didn't go great. She's not terribly excited about it.," he said. "She honestly didn't have a very strong reaction. I was a little bit surprised."
But his readers have had a very strong reaction. He's already gotten dozens of suggestions to fill out his 101 uses.
Some ideas have been vulgar and sexual in nature, which Cotter has quickly erased from the site.
"I want to keep it clean," he said.
His favorite user submitted uses -- a Snuggie and Hammer pants.
"I'm close to so many divorces right now. And it's really sad," he said. "I don't think I'm the only one that has done silly things with an item that was left behind."
Some readers have shared their own divorce horror stories. Others cheer Cotter on.
"I feel for you bud," one reader wrote Tuesday. "Regrettably, I am on my second ex-wife. It doesn't get better."